In recent times gasoline refiners and marketers improve the various qualities of the gasolines supplied to the motoring public by blending a variety of additives with the fuel The need for additives has become ever more important because of the continuing demand by car owners for good engine performance from their high tech engines, while at the same time, keeping costs low and satisfying the needs for high fuel mileage and mandated low emission levels of air pollutants. As a result the oil companies have developed fuel additives and fuel components that are blended with the more-or-less commodity gasoline to improve the octane (anti-knock) quality, remove carbon deposits from combustion chambers and fuel injectors, reduce emissions by adding oxygenates, and so on.
These complex fuel additives developed by the various oil companies are usually proprietary since they are intended to make their brand of gasoline more desirable to the motoring public, thereby causing brand allegiance and repeat customers.
The proprietary additive package, as it is usually called, is normally added at the bulk terminal. If the additive is of low volume, it is usually added when the fuel is loaded into transport trucks for delivery to service stations. Large volume "fuel component" kinds of additives require significant duplicate storage and handling facilities at the terminals. Different wholesale customers get different additive packages, and a given refinery or bulk plant will often supply more than a single chain of branded and unbranded service stations. Additive addition as outlined is complicated, and subject to error. Some additives are volatile and some begin to degrade once mixed with the fuel. Also, in some regions of the country, some additives are going to be mandated by the regional environmental regulators (such as the need for oxygenates for the Rocky Mountain region of the country). Therefore, since a refinery or bulk plant can typically serve a region within a 300 mile radius, it is becoming still more desirable to perform the addition and blending with additives at the service station. Further, since gasoline marketers often add different additive quantities to different fuel grades, it is most desirable to add these to the fuels at the retail fuel dispenser in the service station. This is especially important in the case of mandated addition because the regulatory testing for conformance will likely be done at the retail pump.
An objective of this invention is to provide an automatic fuel additive dispensing system that can be incorporated into service station fuel dispensers which will automatically blend a preset amount of one or more additives into the fuel as it is being delivered into the motorists gas tank. The preset amount of each additive to be blended will be in terms of a specified mix ratio according to the desires of the fuel marketer and environmental regulators. The additive dispenser system will allow the mix ratio for each additive to be set independently, and easily changed from time to time as the additive formulations are changed. Likewise, the additive dispenser will allow the mix ratios for the additives to be set differently for each fuel grade, according to the desires of the marketer.
When the volume of fuel additive blended with the fuel is a significant amount relative to the errors of measurement allowed by the Weights and Measures regulators, the additive volumes must be added to volume of fuel dispensed. For example, when the additive mix ratio is very low, such as in the order of about 1 cubic centimeter, or one milliliter, per gallon of fuel, the mix ratio is only about 0.026%. This is a rather insignificant amount compared to the W&M accuracy requirement of about 0.4% and therefore will probably not be an issue from a W&M standpoint. This is especially true if the additive amount dispensed will be in addition to the fuel volume for which the retail customer is actually charged.
But when the additive is of a larger volumetric ratio and becomes a significant portion of the fuel delivery, relative to the tolerated errors of fuel metering, the measured additive volume dispensed will have to be added to that of the fuel delivery for transaction purposes, and the accuracy of measurement will probably have to meet the 0.4%. This can be accomplished in one of two ways. The simplest and preferred method is to inject the additive into the fuel at a point that is upstream of the meter in the fuel dispenser. In that way the additive is measured along with the fuel. For cases where there is reason to inject the additive downstream of the meter, such as at the nozzle, this invention includes the facility for metering the additive volumes dispensed, and for this dispensed volume data to be transmitted to the fuel dispenser computer on a real time basis during fueling. With this information, the computer will add and include the additive volume dispensed with the metered fuel volumes for sales transaction purposes.
In this extension of the earlier disclosed system in Ser. No. 07/472,236, the choice of the additives becomes that of the gasoline marketer, and not that of the gasoline buying customer. Accordingly, the dispensed additive in this invention will not be the subject of a separate sales transaction. Instead, the additives simply become a part of each of the graded fuel products that the marketer wishes to sell as his proprietary fuel products, and at the posted prices as usual. This invention affords a more desirable, more effective, and much more controlled method of blending fuel additives that are offered by the fuel marketer, that may or may not be mandated by the regulatory authorities. This invention applies to any and all fuel additives, and to fuel components which are generally of larger volume ratios to the fuel volume. The term "additive" is used hereafter in this patent application for all such substances to simplify the wording.
A further objective of this invention is to provide a similar fuel additive dispensing and blending system for use with fuel blending retail dispensers. In these fuel blending dispensers a premium grade of gasoline is blended with a lower grade of gasoline to form one or more selectable intermediate grades of gasoline. For this case, this invention includes the ability to dispense and blend the fuel additives into both of the flowing streams of fuel according to preset mix ratios, or into the blended fuel stream according to preset mix ratios for each selectable grade.
The system comprises:
1. Fuel additive fluid storage tanks PA0 2. Additive pumps with drive mechanism PA0 3. Additive fluid meters PA0 4. A distribution means that automatically directs the pumped and metered additive to the correct fuel line PA0 5. Plumbing as required for the additives from the storage tank to the pump and meter, through the distribution system, and to the point where it is injected into the fuel stream. Normally a dual hose runs to the dispensing nozzle. PA0 6. A controller that: PA0 1. One or more additive fluid storage tanks with these storage tanks properly sized relative to the gasoline storage for normal additive use; PA0 2. a minimum of one additive pump and drive mechanism for each additive storage tank; PA0 3. an additive fluid meter for each different additive to measure additive flow into the gasoline as the gasoline additive mixture is dispensed; PA0 4. a distribution system with control valve that may be controlled to direct additives as measured to the fuel line activated by the customer to dispense fuel; PA0 5. Plumbing as required for the additives from the storage tank to the pump and meter, through the distribution system, and to the point where it is injected into the fuel stream. PA0 6. A controller that:
Note: The additive pump and meter may or may not be a single device such as a metering pump.
a. monitors the existing fuel dispenser system to detect which fuel has been selected by the customer and the fuel flow rate in real time; PA1 b. sets the distribution system so as to deliver additive to the proper fuel line being used; PA1 c. regulates the additive pump motor and/or drive mechanism and in one embodiment, a fuel blend control valve in such a way that the additive pump delivers additive in chosen amounts proportional to the fuel flow rates as the fuel is delivered to the customer's gas tank; and PA1 d. sends additive-volume-dispensed signals to the fuel dispenser computer for inclusion with the fuel volume dispensed if the additive is being dispensed downstream of the fuel flow meter. PA1 (a) monitors the existing fuel dispenser system to detect which fuel has been selected by the customer and the fuel flow rate in real time; PA1 (b) sets the distribution system so as to deliver additive to the proper fuel line being used; PA1 (c) and regulates the motor and/or drive mechanism in such a way that the additive pump delivers additive in chosen amounts proportional to the fuel flow rates as the fuel is delivered to the customer's gas tank; and PA1 (d) sends additive-volume-dispensed signals to the fuel dispenser computer for inclusion with the fuel volume dispensed if the additive is being dispensed downstream of the fuel flow meter.
The controller function includes the capability to be preset to provide mix ratios of additive/fuel that are fixed thereafter, until changed once again. It is also capable of controlling multiple additive blender pumping systems as described above, each with independently set mix ratios as required for each of multiple additive fluids.
In this invention, the additive fluids can be delivered all the way to the fueling nozzle with flexible tubing as is disclosed in the prior referenced invention, or it may be delivered and injected into the fuel stream at some point within the hydraulics section of the fuel dispenser.